Trailer break away switch mount

ABSTRACT

Apparatus comprising an improved mount for a break away switch and a battery box to the chassis or hitch frame of a trailer type vehicle. The mounting bracket protectively retains the switch for selective angular disposition relative the trailer vehicle and has a functional relation to the battery box.

United States Patent Hollander 1 Sept. 12, 1972 [54] TRAILER BREAK AWAYSWITCH MOUNT [72] Inventor: Irvin Hollander, 30 Knollview Place, Dayton,Ohio 45405 [22] Filed: Oct. 1, 1971 [21] Appl. No.: 185,635

[52] U.S. Cl. ..200/6L19, 188/112 [51] Int. Cl. ..ll0lh 27/04 [58] Fieldof Search ....200/6l.l9; 188/112; 340/222,

[56] References Cited UNITED STATES PATENTS Beiswenger ..340/2823,062,326 11/1962 Jones et a]. ..200/6l.19 X

Primary Examiner-Robert K. Schaefer Assistant Examiner'-M. GinsburgAttorney-Jerome P. Bloom [5 7] ABSTRACT Apparatus comprising an improvedmount for a break away switch and a battery box to the chassis or hitchframe of a trailer type vehicle. The mounting bracket protectivelyretains the switch for selective angular disposition relative thetrailer vehicle and has a functional relation to the battery box.

10 Claims, 6 Drawing Figures PATENTEDSEPIEIBYZ 3.691.330

33 g 2/ /a a INVENTOR IRVIN HOLLANDER BYEWM'PZ M A TTOR/VE Y 1 TRAILERBREAK AWAY SWITCH MOUNT BACKGROUND OF THE INVENTION This inventionrelates to a novel kit for mounting a break away switch to the chassisor hitch frame of a trailer type vehicle. It provides a functionalinterrelation between a mounting bracket, the switch and a battery boxenabling an improved and more protective control system for theautomatic braking of the related vehicle, as and when required.

Control assemblies of the class to which this invention relates have astheir objective a means to provide an immediate braking of a relatedtrailer type vehicle when it's towing vehicle is inadvertentlyseparated. The actuation of the control circuit for producing theautomatic braking of the towed vehicle is under the sole control of abreak away switch. Accordingly, the safe, secure, yet accommodatingmount thereof to meet all conditions and requirements of use iscritical. It is also important that the necessary controls be compactlymounted and that there by maximum protection and security in the mountof a battery to power said control circuit.

Heretofore the mounting of the break away switch and the related batteryhave left something to be desired. In some cases the elements of thebraking control system such as afforded by the invention have beenprovided in separate component forms such that the switch and thebattery elements thereof have required their individual mounting on thetowed vehicle. This has been disadvantageous from the standpoint oflending itself to awkward disposition of the elements by inexperiencedpersonnel and possible malfunction of the system as a result thereof. Anadditional problem evidenced in the prior art has been in the nature ofthe mount and the inadequate protection of the battery so essential toproviding the necessary power source for the braking system.Furthermore, the mounting heretofore provided for break away switches inthe prior art apparatus of the class described has been inadequate toprevent tampering and inadvertent loss of the switch. In many instancesthe nature of the switch mount has been such that it has been toorigidly fixed, leading to incidents of premature braking of the relatedvehicle. It has also happened that the switch mount was too free and didnot function when required.

SUMMARY OF THE INVENTION The present invention is directed to overcomingthe above mentioned problems in the related art. It provides for acompact and secure incorporation in a trailer type vehicle of a breakaway switch and a battery. The switch is so mounted to be selectivelypositionable for alignment with a towing vehicle through the medium ofan actuating cable. Nevertheless, the switch is contained againstinadvertent removal or displacement. While accommodating a degree ofmisalignment between the towing and the towed vehicle, movements of theswitch are limited to insure its actuation in the event of an actualseparation in the hitch between the towing and the towed vehicle.

In a preferred physical embodiment, the invention provides a switchmounting bracket incorporating simplified fastening means for a quickand easy attachment thereof to the trailer chassis or hitch frame. Thebracket is so designed as to interconnect therewith and functionallyrelate to a box or receptacle for protective retention of a battery.

The invention embodiments to be here illustrated features simplicity,economy of fabrication and an inherent ability to inhibit malfunction ina break away control between a towing and a towed vehicle.

It is therefore a primary object of the invention to provide a new andimproved assembly of the primary components necessary to provide a breakaway control between a towing and a towed vehicle which is economical tofabricate, more efficient and satisfactory in use, adaptable to a widevariety of applications and unlikely to create malfunction.

Another object of the invention is to provide for mounting of a switchunit in a break away control assembly disposed between a towing and atowed vehicle in which the switch will accommodate selective positioningwithin a normal range of displacement between a towing and a towedvehicle without danger of malfunction.

A further object of the invention is to provide a mounting device for abreak away switch incorporated in an automatic braking system for atowed vehicle which inherently secures the switch against inadvertentdetachment from the towed vehicle and inhibits tampering while enablingthe switch to accommodate an adjustment in position without actuatingthe related braking system except as and when needs require.

Still another object of the invention is to provide a break away controlassembly, the components of which are constructed for weather and impactresistance and which combine features of integration and security withan adjustability lending versatility to the mounting and use of theassembly.

An additional object of the invention is to provide a break away controlassembly for mounting to a trailer type vehicle and components thereofpossessing the advantageous structural features, the inherentmeritorious characteristics and the means and mode of use hereindescribed.

With the above and other incidental objects in view as will more fullyappear in the specification, the invention intended to protected byLetters Patent consists of the features of construction, the parts andcombinations thereof, and the mode of operation as hereinafter describedor illustrated in the accompanying drawings, or their equivalents.

Referring to the drawings wherein are shown one but not necessarily theonly form of embodiment of the present invention,

FIG. 1 is a perspective view showing a break away control assembly inaccordance with one embodiment of the invention, in an installedposition;

FIG. 2 is a detailed view in perspective of the switch unit comprised inthe assembly of FIG. 1;

FIG. 3 is a side view of the control assembly of FIG. 1;

FIG. 4 is a fragmentary top plan view of a bracket comprised in thecontrol assembly, showing mounting means for the switch unit;

FIG. 5 is a fragmentary view in cross section, showing the switch unitlockingly positioned in the mounting bracket; and

FIG. 6 is an open perspective view showing features of the battery boxembodied in the control assembly.

Like parts are indicated by similar characters of reference throughoutthe several views.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings, a breakaway control assembly in accordance with the illustrated embodiment ofthe invention includes a mounting bracket which may be made of a rigiddurable plastic material but which in the illustrated instance is aformed metal part suitably coated or plated to be corrosion resistant.The bracket 10 is a flat sheet-like member of rectangular configuration,the opposite ends of which are turned down differential distances toform a long leg 11 and a shorter leg 12 dependent from the respectiveends of an intermediate generally planar web section 13. Beads 14 and 15are formed along side margins of the bracket 10 to impart greaterstrength and rigidity to the substance thereof. In cross section, thebracket 10 has an inverted U-shape and is adapted to fit over a mountingbar 16 square in cross section and forming a part of the hitch frame orother stationary chassis part of a towed vehicle. As mounted, the legs11 and 12 achieve an embracing relation to opposite side faces of thebar 16 while the planar web portion 13 seats substantially flush to thetop surface of the bar. The relatively shorter leg 12 of the bracket 10has a threaded aperture in which is mounted an angle shaped screw member17. As will be self-evident, the screw member 17 is relatively rotatableto advance one end upon and to retract the same from a side surface ofthe bar 16 in a manner to cause bracket 10 to be fixed to the bar or tobe released therefrom.

In a central location in the web 13, a deformed portion is displacedoutwardly from the plane thereof and the underlying surface of bar 16 todefine a concavoconvex boss 18. The latter has a truncated configurationand presents a flat planar surface extremity l9 outermost, which surfaceis substantially parallel to web 13. Centered in the planar surfacedextremity 19 is an aperture 21. The portion of said planar surfaceextremity 19 which rims the aperture has formed therein a pair ofdiametrically opposite notches 22, the purpose of which will be furtherdescribed.

The aperture mounting screw member 17 and the boss 18 are substantiallycoincident of one another in a line defining introduction into to lidthe longitudinal axis of the sheet-like member forming the bracket 10.In the same line but offset to an immediately adjacent relation to leg11, a rectangular loop portion of web 13 is outstruck to form integraltherewith a perpendicular vertically projected latch member 23. Themember 23 disposes substantially as an upward extension of the leg 11.

The leg 11 of bracket 10 serves further as a wall support for themounting thereto of a battery box or receptacle 25. The leg 11 isrelatively reduced in width in reference to web 13, from side to sidethereof, to.

facilitate its introduction into channel shaped guides 27 formedintegral with a front wall surface 26 of the box 25, whereupon suitablemeans are applied to fix the wall 26 of the leg 11. The box 25 iscomprised of a container and lid, the container being formed by thefront wall 26 and interconnected end, bottom and back walls. Thecontainer is open at its top to accommodate the insertion therein of abattery. A notch or recess 29 formed in the upper edge of the front wall26 of the battery container provides a wire passing opening. The opentop of the battery container is capped by a lid member 32 having adependent peripheral wall integrally connected by a section of flexiblestrap-like material to the back wall of the container. This integralstrap forms a lie hinge 31 to the back of the container which isdisposed outermost in reference to the leg 11 of the bracket 10. A notch33 is formed in a front dependent wall portion of the lid 32 adapted toregister with the notch 29 in the container wall 26. The registration ofthe notches 29 and 33 provides an opening accommodating the passage ofsuch lead or leads as may be required or completing a control circuitembodying the applied breakaway switch. Further, positioned centrally onthe front dependent wall portion of the lid 32 and projected outwardlytherefrom is a lug 34. The latter is adapted to align with and tofrictionally engage in the opening defined by the loop formed latchmember 23 for maintaining the lid in a closed relation to the containerportion of the battery box 25. The dependent wall portion of the lid isdeflectable, as is the lug 34, and has sufficient resilience as to tendto normally project the lug for interengagement in the latch member 23.When release is desired, this is accomplished by pressing inwardly uponthe dependent front wall portion of the lid, whereupon lug 34 isdisengaged from the latch 23 and the lid may be raised on its integralhinge structure.

Thus, the battery box 25 is simply but effectively connected to the leg11 of the mounting bracket 10 and, as may be seen, the nature andrelation of the container and lid portion thereof which are impermeablein character is such to provide a fully protective weatherproofenclosure for a battery. Note, in particular, that the integrally hingedlid 32 is lockedto the mounting bracket through the medium of the lug 34and the latch 23. There is therefore a functional relation between thebattery box and the mounting bracket to preserve the integrity of theseal provided in the containment of the battery.

The battery box or receptacle 25 may be mad of any material suitable toits intended purpose. However, preferred embodiments will be made of amolded, impact resistant, plastic. It is emphasized that in accordancewith the invention all parts of the battery box will have an integratedrelation to one another, the

hinge 31 being unitarily integrated with the container and lid portionsof the box and the guides 27 and lug 34 being formed as integralprojections on surface portions of the box.

Further comprised in the control assembly of the invention is the switchunit 35. Unit 35, as shown, has a generally rectangular configuration asembodied in an external housing 36, the latter of which is alsoconveniently made of a plastic material and secured by bolts or rivets37 to a mounting plate 38. In use the plate 38 forms a base for theswitch unit 35 and it is therefore made of a rigid durable materialwhich may conveniently correspond to or. be the same as the material ofwhich bracket 10 is fabricated. Positioned within the housing 36 are thenet required switch elements, the details of which are unnecessary to aconsideration of the present invention. Viewing the drawings, from anaperture in the side of the housing 36 project a pair of insulatedelectrical conductors 39 and 41. One of said-conductors leads to thebattery box 25 to enter the same through the opening defined by theregistration of the notches 29 and 33. The other conductor is extensiblefrom the switch unit 35 to connect into an electrical control system, inthis casea braking control system for the related trailer type vehicle.Operation of the switch elements within the switch unit 35 is under thecontrol of a key member 42 slidably installed in the switch unit andextending through and outwardly of one end of the housing 36. At itsouter projecting end, key 42 is formed with an eye 43 through which oneend of a flexible cable 44 is looped and so connected. The cable 44extends from the switch unit to have the opposite end thereof, which isformed as a loop 45, to be applied in connection with a stationary partof a towing vehicle. In a manner which it is unnecessary here toconsider, the key member 42, when fully inserted into the switch unit35, maintains the switch elements therein in a predetermined position ofadjustment. The key member has a detented retention within the switchunit but if sufficient pull is applied through the cable 44, it issubject to partial or complete withdrawal from the switch unitto allowthe switch elements to assume an alternate control position. In thiscase the alternate control position will provide the actuation ofcontrols for automatic application of the brakes in the trailer or towedvehicle.

At an end of the switch unit 35 opposite to that from extends beyond theadjacent end of housing 36. The

projecting end of plate 38 provides a flat portion 46 coplanar withthat-part of the plate underlying case 36. Outwardly of the switch case,planar portion 46 tapers and at its outer or apex end terminates in anextended section 47 of uniformly reduced width. The latter in turnmerges with a relatively broad tongue 48. Section 47 is bent downwardlyout of the plane of the portion 46 and the tongue 48 is bent forwardlyto dispose substantially parallel but in offset relation to planarportion 46. The tongue 48 has a rounded or continuously curved leadingedge and formed with rearwardly facing shoulders 49 and 51 onrespectively opposite sides of the reduced section 47, the latterforming a neck in a connecting relation to tongue 48 and plate portion46.

The switch unit has the plate configuration 46-51 to facilitate itsmounting in the bracket and in selective positions of adjustment. Thismounting of the switch unit is accomplished prior to mounting of thebracket to the bar 16. Tongue 48 of neck 47 achieves a directlycooperative relation with boss 18 in the bracket to bring about theswitch mounting. In the assembly of the switch unit to the bracket 10,switch unit 35 is held substantially perpendicular to the bracket 10 andtongue 48 is insertedthrough the boss 18 'on a diametral line defined bythe notches 22, the latter of which accommodate the lateral extremitiesof the tongue 48 on insertion. By this means, the tongue which has amaximum width which exceeds the diameter of the aperture 21 is readilyaccommodated in passage through the extremity 19 of the boss 18. Neck 47has a width approximately corresponding to the diameter of aperture 21.With the tongue 48 fully inserted through boss 18, neck 47 adjacent thetongue disposes in the plane of the projected planar portion 19,whereupon the switch unit may be turned to a selected angular positionof adjustment relative to the bracket 10 and lowered in such positionand to approximate parallelism with the bracket as indicated in FIG. 1.Lowering motion of the switch unit is limited by engagement of thetongue portion 48 with the underside of planar portion 19, the plateportion 46 at neck 47 limiting similarly against the planar portion 19on the exterior or outer surface thereof. The unbalanced weight of theswitch unit is thus applied in a manner to urge tongue 48 upwardlyagainst bracket portion 19, whereupon the side edges of neck portion 47substantially contact the inner edge of aperture 21. Thus, tongue 48 iscompletely received within the boss 18 of the bracket 10 and, in theinstalled portion of the assembly, is secured against detachment, sinceto remove the switch unit it must be free to be tilted back to aperpendicular position so the tongue may be withdrawn vertically in linewith and through the notches 22. v

In assembling the several components of the break away control device,the screw member 17'is installed in mounting bracket 10 by being rotatedinto its aperture in the leg 12. Bracket leg 11 is inserted in theguides 27 therefor defined on the front wall 26 of the container portionof the battery box 25. Forsecurity, a rivet or other means of attachmentis used to fix the front wall of the battery receptacle to, the leg 11.Switch unit 35 is tilted into a vertical position in respect to thebracket web portion and the tongue 48 inserted on a line through notches22 in the boss 18 of bracket 10. The switch unit may be then selectivelypositioned angularly of the bracket depending on its desired orientationin place. The position the switch unit will normally assume will be onesubstantially parallel to the battery box 25, with the switch unitassuming either the opposition shown in FIG. 1 or a position displacedtherefrom, according to the attitude of the bracket 10 in the mountingthereof to a bar 16. The arrangement normally will be one tosubstantially align the switch unit with the towed and towing vehiclesso that when a pull is exerted through the cable 24 from the towing tothe towed vehicle, the pull will be substantially axial in relation tothe key member 42. Note that this will obviate the chances of damage tothe switch unit in break away action. Considering further the assembly,bracket 10 is then mounted to a support bar 16 and the screw member 17turned to lock the assembly in place thereon. In mounting the bracket 10to the bar 16, web portion 13 seats in a substantially flush manner tothe upper surface of the support bar which accordingly provides a bottomwall in enclosing relation to the underside of boss 18. The tongue 48 isaccordingly then contained and locked within the boss. It is preventedby the underlying support bar from tilting to a position necessary toenable withdrawal of a tongue through the boss. The switch unit isaccordingly securely held against inadvertent or unauthorized removalfrom the assembly and cannot be detached except as part of an operationdetaching the entire assembly. Once the assembly is applied to the bar,a battery may be inserted in the container portion of the box 25 and thelid closed thereon, automatic latching of the lid then taking place, byvirtue of the resilient interconnection of lug 34 in the latch loop 23.

In connecting the control assembly to operating parts of the towed andtowing vehicles, key member 42 is inserted fully within the switch unit35 and cable 44 extended therefrom and attached to a fixed location onthe towing vehicle. The electrical conductors 39 and 41 areappropriately applied in a conventional manner to incorporate thebattery and the switch in a control system applicable to the brakes ofthe related trailer type towed vehicle. Since the details of the circuitare not necessary to an understanding of the invention, they are notfurther described. Suffice it to say that on pulling of the key member42 outwardly of the switch unit 35; in the case of an inadvertentseparation of the towing from the towed vehicle, the switch willfunction to cause the related circuit to function in a manner to producean application of the trailer brakes.

Note the mount of the switch to the boss 18 is such to permit limitedrotative displacement such as necessary to accommodate slightmisalignment of the towed and the towing vehicle. Yet excessive freedomof turning movement of the switch unit is inhibited by virtue of therelationship of the neck 47 and the notches 22 in the boss portion 19.It will be seen that the relatively close fit of neck 47 and aperture 21enables that where there is a lateral force applied in turning of theswitch side edges of the neck will engage in and limit against therespective edges of the notches 22. Thus, there is a limitedaccommodation and defined limits in respect to turning movement of theswitch unit 35 relative its mounting medium. The net result will be asure and certain and relatively direct pull on the key member 42 as animmediate consequence of an undue separation or dangerous misalignmentof the towed and towing vehicle.

In summary, the invention achieves a simple but effective improvement inassemblies available for application of break away control switches totrailer type or towed vehicles.

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeatures of advantage before enumerated as desirable, but whichobviously is susceptible of modification in its form, proportions,detail construction and arrangement of parts without departing from theprinciple involved or sacrificing any of its advantages.

While in order to comply with the statue the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise but one of several modes of putting the invention into effectand the invention is therefore claimed in any of its forms ormodifications within the legitimate and valid scope of the appendedclaims.

Having thus described my invention, 1 claim:

1. Break away control apparatus for installation between towed andtowing vehicles, the towed vehicle having an electrically controlledbraking system: comprising a bracket for mounting in connection with onevehicle, a battery box carried by said bracket, a switch unit carried bysaid bracket and differentially positionable thereon, said switch unitand a battery when inserted in said battery box providing meansadaptable for connection thereof to provide a control for theelectrically controlled braking system, and said switch unit including aswitch actuating member adaptable for attachment thereof to the other ofsaid vehicles.

2. Apparatus according to claim 1 characterized by means for detachablymounting said bracket to the towed vehicle, said bracket and saidbattery box and said switch unit being interrelated and forming anassembly attachable and detachable as a unit with respect to the towedvehicle.

3. Apparatus as in claim 1 characterized by the application of saidbracket and said switch unit in assembled relation producing acontainment of said switch unit to a structure to which said bracket ismounted.

4. Apparatus according to claim 3 wherein said bracket presents anundersurface portion of which is adapted for flush mating contact with asurface of the structure in connection with said towed vehicle andanother portion of which is displaced from said surface, said anotherportion having an opening therein, said switch unit having a portioninsertable through said opening and upon insertion adapted to becontained for limited movement within and with respect to said displacedportion.

5. Apparatus according to claim 4, characterized by said displacedportion forming a boss on the upper surface of said bracket, said bosshaving an aperture intersected by diametrically aligned notches, saidinsertable switch portion providing a tongue having a relatively wideextremity to be inserted on a line through said notches and a relativelynarrow neck portion to be accommodated in the aperture in said boss,said tongue being adapted to be received in said displaced portion to beconfined therein by the application of said bracket to the said surfaceof the towed vehicle.

6. Apparatus according to claim 1, wherein said bracket provides arelatively broad flat planar section a localized portion of which has aconcavo-convex configuration intersected by transverse slots, saidswitch unit having a projecting mounting flange terminating in a tonguein a substantially offset parallel relation to the flange and connectedthereto by a reduced neck portion, said switch unit in a substantiallyperpendicular attitude relative to said bracket positioning said tonguefor insertion through said slots from the convex side of said localizedportion of said bracket section, said tongue in a lowered attitude ofsaid switch unit disposing substantially parallel to said planar sectionof said bracket and being lockingly received in said concave side ofsaid localized portion of said bracket.

7. Apparatus according to claim 1, wherein said bracket has a channelshape presenting substantially parallel legs interconnected at their oneends by a transverse web portion, one of said legs providing a panel forattachment of the battery box thereto and said transverse web portionbeing formed with means for the attachment of said switch unit theretoin selected angular positions of adjustment.

8. Apparatus according to claim 7, wherein said bracket is constructedto mount on a part of the towed vehicle of substantially complementaryconfiguration, the other leg of said bracket carrying means to tightenand to release said bracket relatively to said part.

9. Apparatus according to claim 7, wherein said battery box has a lid,portion of said transverse web of said bracket being outstruck therefromto form a detent in UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION l l 1 .n Patent No. 3,691,330 Dated September 12, 12 Z;

Inventor(s) Irvin Hollander y it is certified that error appears in theabove-identified patent and that said Letters Patent arehereby correctedas shown below:

Col. l, line 22, "by" is corrected to read be Col. 2, line 45, insert"be" following to Col. 3, line 48, delete "introduction into to lid".

Col. 3, line 63, "to" is substituted for of Col. 4, line 7, "lid" issubstituted for lie Col. 4 line 44 "made" is substituted for mad Col. 6,lines 37-38, "position" is substituted for opposition Signed and sealedthis 13th day of February 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM PC4050 USCOMM-DC 00376-P60 LL, GDVIIIININT PRINTINGO'FICI: ill. O)l,4

UNITED STATES PATENT OFFTCE- CERTIFICATE OF CORRECTION Patent No.5,691,330 Dated September 12 1972 Inventor(s) Irvin Hollander It iscertified that error appears in the above-identified patent and thatsaid Letters Patent arehereby corrected as shown below:

Col. 1, line. 22, "by" is corrected to read be Col. 2, line 45, insert"be" following to Col. 3, line 48, delete "introduction into to lid")Col. 3, line 63, "to" is substituted for of Col. 4, line 7, "lid" issubstituted for lie Col. 4 line 44 "made" is substituted for mad Col. 6,lines 37-38, -"position" is substituted for opposition Signed and sealedthis 13th day of February 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCI-IALK Attesting Officer Commissionerof Patents FORM uscomwoc 00376-P60 i .5. GOVERNMENT PRINTING OFFICZ Ill'-3..-Jl

1. Break away control apparatus for installation between towed andtowing vehicles, the towed vehicle having an electrically controlledbraking system: comprising a bracket for mounting in connection with onevehicle, a battery box carried by said bracket, a switch unit carrIed bysaid bracket and differentially positionable thereon, said switch unitand a battery when inserted in said battery box providing meansadaptable for connection thereof to provide a control for theelectrically controlled braking system, and said switch unit including aswitch actuating member adaptable for attachment thereof to the other ofsaid vehicles.
 2. Apparatus according to claim 1 characterized by meansfor detachably mounting said bracket to the towed vehicle, said bracketand said battery box and said switch unit being interrelated and formingan assembly attachable and detachable as a unit with respect to thetowed vehicle.
 3. Apparatus as in claim 1 characterized by theapplication of said bracket and said switch unit in assembled relationproducing a containment of said switch unit to a structure to which saidbracket is mounted.
 4. Apparatus according to claim 3 wherein saidbracket presents an undersurface portion of which is adapted for flushmating contact with a surface of the structure in connection with saidtowed vehicle and another portion of which is displaced from saidsurface, said another portion having an opening therein, said switchunit having a portion insertable through said opening and upon insertionadapted to be contained for limited movement within and with respect tosaid displaced portion.
 5. Apparatus according to claim 4, characterizedby said displaced portion forming a boss on the upper surface of saidbracket, said boss having an aperture intersected by diametricallyaligned notches, said insertable switch portion providing a tonguehaving a relatively wide extremity to be inserted on a line through saidnotches and a relatively narrow neck portion to be accommodated in theaperture in said boss, said tongue being adapted to be received in saiddisplaced portion to be confined therein by the application of saidbracket to the said surface of the towed vehicle.
 6. Apparatus accordingto claim 1, wherein said bracket provides a relatively broad flat planarsection a localized portion of which has a concavo-convex configurationintersected by transverse slots, said switch unit having a projectingmounting flange terminating in a tongue in a substantially offsetparallel relation to the flange and connected thereto by a reduced neckportion, said switch unit in a substantially perpendicular attituderelative to said bracket positioning said tongue for insertion throughsaid slots from the convex side of said localized portion of saidbracket section, said tongue in a lowered attitude of said switch unitdisposing substantially parallel to said planar section of said bracketand being lockingly received in said concave side of said localizedportion of said bracket.
 7. Apparatus according to claim 1, wherein saidbracket has a channel shape presenting substantially parallel legsinterconnected at their one ends by a transverse web portion, one ofsaid legs providing a panel for attachment of the battery box theretoand said transverse web portion being formed with means for theattachment of said switch unit thereto in selected angular positions ofadjustment.
 8. Apparatus according to claim 7, wherein said bracket isconstructed to mount on a part of the towed vehicle of substantiallycomplementary configuration, the other leg of said bracket carryingmeans to tighten and to release said bracket relatively to said part. 9.Apparatus according to claim 7, wherein said battery box has a lid,portion of said transverse web of said bracket being outstruck therefromto form a detent in cooperation with a portion of the lid of said boxyieldingly to hold said lid closed.
 10. Apparatus according to claim 9,wherein said battery box and lid are formed as a unitary molded plasticor like article, the lid and box being interconnected by an integrallyformed hinge.